ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Changes in accumulated other comprehensive income (loss) [Abstract]
Net foreign currency translation adjustment	$ (1,089)	$ 1,363
Net change in postretirement benefit plan (see Note 15 for further information)
Amortization of prior service cost	18	18
Amortization of gain	(11)	(1)
Total before tax	7	17
Tax	(2)	(4)
Net of tax	5	13
Other comprehensive (loss) income	$ (1,084)	$ 1,376

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Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature, attributable to parent entity.

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Amount after tax of other comprehensive income (loss) attributable to parent entity.

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